Means for identifying materials



pound in the form of a fine powder, may be invention, and I, therefore, do not purpose 9o Patented July/29,1 1930 1,7 71,612"

UNITED STATES PATENT OFFICE DAVID JULIAN BLOCK, OF CHICAGO, ILLINOIS MEANS FOR IDENTIFYING MATERIALS No Drawing. Application filed January 26, 1928. Serial No. 249,776.

This invention relates to means for identidusted over the surface of the paper, and the fying materials, and more particularly to excess powder removed, or the paper may means for detecting alterations in checks and be treated with a solution of the compound,

other valuable instruments. or small quantities of the compound may be I have found that certain substances possess incorporated in the fibers during the manuthe property of fluorescing under the influfacture of the paper. 50

once of ultra-violet light. This property in The compound that I prefer to use for certain instances is so extremely marked that treating paper and the like is aesculin, which infinitesimally small amounts of a particular has a formula-C H O +l/2H O which is substance may be spread upon or incorporated a glucoside obtainable from the barks of cerinto material such as checks and the like and tain trees in the form of a White powder. still retain their fluorescing properties. One application of my invention would be It is therefore an object of this invention the detecting of fraudulently altered checks to provide means for identifying materials or the like. Where the checks are made of by the incorporation therein of substances paper surface treated as above, any erasure 0 having strong fluorescent properties under upon the face of the check would show. up un- 60 the action of ultra-violet light; der an ultra-violet light as a dark area free It is a further object of this invention to of fluorescence. For the examination of the provide a safety paper that cannot be altered checks, an ultra-violet light could be suit- 0 or tamperedwith, Without being capable of ably positioned in the counter by the tellers ready detection when observed under the ac- WlIldOW n he a f0Ii S a 1Ce,With a plate 0 ti f uit i l t li ht, I of quartz glass or the like over the ultra- Other and further important objects of this ViOlet g t lush with the surface of the invention will become apparent from the fol- COuIltBT- I this Way the teller Would merelowing description and appended claims. 1y pass the check over the light and thus ex- VVhil thi i ti i li bl t n am ne it in the regular routine of business. purposes and in connection with the identifi- IP obvious that the identifying compound cation of many substances, it will be hereinmlght be r anged upon the surface of the d ib d i connection ith th f check in theform of a particular design or in {3 113 and use of afety paper, Paper to be figures SO that one examining the paper COllld used for the manufacture of checks, bank a l at a glance'whether or notit were gennotes and other valuable instruments may be 111118- so treated according to my method that al- My lnventionis also intended to cover the teration as by erasure, chemical. or other 0 f a fluorescing material in the ink used means, can be readily detected. According to 1 pllnting a design upon checks or the like, my invention, the paper is treated with a suba g With coloring matters su face stance having high fluorescing properties untinting papers. It is also intended to cover der the influence of ultra-violet light. Sub the use of fluorescing material in the ink emstances that have proven suitable for this p yed f I" making indicia, such as the 40 purpose are aesculin, quinine and its salts, amount or value of the instrument, upon the 35 uranium salts, salicylic acid and the like. fa f the paper. The treatment of the paper with these par- I am aware that numerous details of the ticular compounds may be carried out in vaprocess may be varied through a wide range rious ways; for instance, the particular com- Without departing from the principles of this Cal limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention a paper containing In testimony wh scribed my name Illinois.

ac'scuhn.

ereof I have hereunto subat Chicago, Cook County,

D. JULIAN BLOCK. 

